1. Field of the Invention
The present invention relates to a pipe store for SZ stranding of electrical and/or optical stranding elements.
2. Description of the Prior Art
Stranding devices of the type mentioned above are known, for example, from the German Letters Patent 682,267, fully incorporated herein by this reference, whereby a rotating stranding disc is provided at the output of a pipe store. The basic structure of such a stranding device is illustrated in FIG. 1, whereby the pipe store, serving as a guide and storage member, is referenced RO. The pipe store RO is alternately rotated for a specific time in the one direction or, respectively, the opposite direction (as indicated by the double-headed arrow RE) over a reversibly functioning drive (for example, in the form of a toothed belt ZR). The drive, for example, can occur over a gear wheel attached to an extension of the pipe store RO, the gear wheel being moved by a toothed belt. The stranding elements, of which only one is illustrated in the present example and referenced VE, are conducted over a stationary perforate guide disc FS at the input side which exhibits a corresponding plurality of axially-extending bores for receiving the stranding elements VE. At its periphery, the perforate guide disc FS is rigidly connected to a corresponding frame or housing. A stranding disc VS which exhibits corresponding axial bores for receiving the stranding elements VE is provided at the output of the pipe store RO. The stranding disc VS is rotatably seated at its periphery by way of a bearing LAV, is rigidly connected to the pipe store RO or, if necessary, can also be separately driven. The stranding elements VE are conducted over a stranding nippe VN at the output of the SZ stranding device. The bearing at the input side is referenced LAE and the "chucking length" of the pipe store RO is referenced l.
Depending on the frictional engagement, the supplied stranding elements VE unwind on the outside of the rotating pipe store RO and thereby transfer the arising torque from the locations of greatest unwinding in the area of the perforate guide disc FS to locations of weaker unwinding in the area of the stranding disc VS. Since the stranding disc VS itself represents a payout brake, torques are transmitted from the intake area at the disc FS to the stranding area depending on the distribution of the frictional forces, in particular, faster or slower depending of the torsional stiffness of the stranding elements VE. The braking torques are compensated directly, or delayed, in the stranding area at the stranding disc VS, so that the stranding itself occurs with only slight or even no torsion. Frictional forces of the pipe store normally consisting of steel which are too high interfere with the distribution of the stranding elements on the pipe store and with the stranding operation itself. On the one hand, they lead to a modulation of the forces at the stranding point which depends on the content of the store and, on the other hand, they effect too high a concentration of the store cabling at the entry side under certain conditions. This can be combatted under certain conditions by additional measures, for example, by an idle pipe piece matched in length, or by other techniques.
A further difficulty in the operation of such pipe stores is that the polar moments of inertia of the pipe are frequently undesirably high for a low drawing or switching. Particularly given great lengths, the high specific weight also leads to an undesired sag of the pipe and to low resonant frequencies which can still lie in the range of operating speeds.